Glycosaminoglycans (GAGs) of the bovine oviduct and follicle (chondroitin sulfate) and cumulus-oocyte complex (hyaluronic acid) caused increased acrosome reactions in sperm. This is time (9 h) and calmodulin dependent, inhibited by seminal plasma and occurred in vivo only in the ampulla of estrual cows. Additionally, bovine sperm incubated with cumulus enclosed oocytes had prolonged and increased motility. We hypothesize that products of the oviduct, follicle or egg cause sperm to undergo the acrosome reaction and enhanced motility in mammals through steps or products similar to egg products which prepare sperm for fertilization in invertebrates. We propose to test hypotheses supporting the following aims: 1) To determine how glycosaminoglycans cause sperm to udergo the acrosome reaction by use of a calcium dependence test to separate effects on capacitation from the acrosome reaction, and by characterizing the binding of GAGs to sperm using 3H and fluorescent labeled GAGs and by determining if seminal plasma alters this process. 2) To determine the source and role of GAGs in causing the acrosome reaction and the time in vivo using a validated staining assay on sperm recovered from the uterus, isthmus and ampulla of the oviduct of luteal, estrual and postovulatory cows and assay of the composition of GAGs at each site and stage and their ability to cause an acrosome reaction in vitro. 3) To determine the separate roles of the cumulus cells and zona pellucida in causing an acrosome reaction in vitro and to identify GAGs in zonae. 4) To determine species-specificity of egg products promoting the acrosome reactions by testing effects of bovine GAGs on hamster and sea urchin sperm and the sea urchin acrosome activator fucuse-6-sulfate on bovine and hamster sperm. 5) To determine the effect of egg products on enhanced motility by characterizing motility patterns and identifying and characterizing the source of the stimulant and comparing its effect across species with the sea urchin motility stimulant, "speract". These experiments will enhance our understanding of the way in which mammalian sperm are prepared for fertilization by products of the egg or female in vivo and in vitro and should identify mechanisms common for vertebrates and invertebrates.